The effects of ozone heating on the linear stability of lower stratospheric traveling waves of the summertime, extratropical circulation are examined. Based on coupled equations for the quasigeostrophic potential vorticity and ozone volume mixing ratio, it is shown that the diabatic heating arising from ozone advection can offset the damping due to Newtonian cooling, leding to wave amplification and significant changes in the structure and zonally rectified fluxes of the wave fields in both the lower stratosphere and troposphere. The vertical profile of the zonal mean wind plays a crucial role in determining whether the ozone heating destabilizes eastward and/or westward traveling disturbances. ¿ American Geophysical Union 1994